Printing plate mounting apparatus, printing plate replacement apparatus and printing plate replacement method

Abstract

A printing plate mounting apparatus is disclosed, which comprises a de-mounting and a mounting lever provided on an end of a lock shaft provided in a printing cylinder and printing plate replacement drive means including air cylinders or the like. With the printing cylinder held at a predetermined position, the drive means pushes each lever to rotate the lock shaft. In this way, the rotational driving of the lock shaft and coupling and de-coupling of the driving are effected collectively. A printing plate replacement apparatus is also disclosed, which comprises roller drive means including a roller and a cylinder or the like. When mounting a printing plate, the roller is urged against the printing cylinder via the printing plate. Otherwise, the roller is retreated by the roller drive means.

What is claimed is: 
     
       1. A printing plate mounting apparatus comprising a lock shaft carried in and extending in the axial direction of a printing cylinder at a predetermined locality of the printing cylinder periphery, said lock shaft serving to lock the ends of the printing plate at its predetermined lock position and unlock the ends at its predetermined unlock position, and lock shaft drive means for moving said lock shaft to said lock position while said printing cylinder is at a predetermined mounting position and moving said lock shaft to said unlock position while said printing cylinder is at a predetermined de-mounting position, said lock shaft drive means including a mounting lever and a de-mounting lever, said levers being secured to an end of said lock shaft and projecting circumferentially opposite directions of said printing cylinder on the opposite sides of said lock shaft, and printing plate replacement drive means for rotating said lock shaft in a locking direction in contact with said mounting lever when said printing cylinder is at said mounting position and rotating said lock shaft in an unlocking direction in contact with said de-mounting lever when said printing cylinder is at said de-mounting position.   
     
     
       2. The printing plate mounting apparatus according to claim 1, wherein said mounting and de-mounting positions are the same, and said printing plate replacement drive means includes a plurality of cylinder means each having a contact member capable of being advanced and retreated with respect to said printing cylinder, the contact member of one of said cylinder means being capable of being brought into contact with said mounting lever, the contact members of the other cylinder means being capable of being brought into contact with said de-mounting lever. 
     
     
       3. The printing plate mounting apparatus according to claim 1, wherein said mounting and de-mounting levers are fitted on an end of said lock shaft and retained by stoppers. 
     
     
       4. The printing plate mounting apparatus according to claim 1, wherein said mounting and de-mounting positions are different, and said printing plate replacement means cylinder means having a contact member capable of being advanced and retreated with respect to said printing cylinder, said contact member of said cylinder means being capable of being brought into contact with both of said mounting and de-mounting levers. 
     
     
       5. The printing plate mounting apparatus according to claim 1, wherein said mounting and de-mounting positions are different, and said printing plate replacement drive means includes a contact member, which is capable of being advanced and retreated with respect to said printing cylinder and being brought into contact with said de-mounting lever to rotate said lock shaft to said unlock position when said printing cylinder is at said de-mounting positions, and a cam member, which is formed on an end portion of said contact member and guides said mounting lever in a predetermined direction to rotate said lock shaft toward said lock position when said printing cylinder approaches said mounting position during forward rotation.